An update rolled out yesterday to Avast's antivirus product contained a bug that flags legitimate Web sites as malware infected.

In a blog post late yesterday, Avast acknowledged the false positive glitch in an update known as 110411-1, which was automatically rolled out to Avast AV users earlier that day. The error has specifically affected versions 4.x, 5.x, and 6.x of Avast's antivirus software.

In an e-mail to CNET, an Avast spokesman said today that the update was downloaded by around 5 million users, mostly on the Western Hemisphere due to the time in which it was launched.

More: http://news.cnet.com/8301-1009_3-20053085-83.html